Across the Border (1922)

Cowboy Andy Fowler rescues a man from a burning cave. It turns out that the man is a member of a gang of rustlers, and out of gratitude, the gang makes Andy one of its own, letting him wear a green armband that signifies his status as a gang member. Despite her love for him, Margie Landers reports him to the sheriff when her father's cattle are stolen. The sheriff has two problems: he is secretly in love with Margie; and, he is actually the head of the rustler gang.